JPS60192950A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To improve mechanical characteristics, thermal stability, etc. by using a specific polycarbonate resin for a binder of an electric charge transfer layer. CONSTITUTION:The electric charge transfer layer of an electrophotographic sensitive body of a lamination type provided with a charge generating layer and charge transfer layer on a conductive substrate contains a charge transfer material and a polycarbonate resin which is obtainable from bisphenol Z and phosgen and is expressed by the formula. The binder is required to be less deteriorated against electrical, mechanical, thermal and optical hazards as a result of use and to decrease the deterioration in the characteristics by the effect of environment in addition to performance such as electrification characteristic, sensitivity, less residual charge, etc. The polycarbonate obtainable from bisphenol A is also excellent in the above-mentioned performance but the polycarbonate obtainable from bisphenol Z has much better characteristics as said polycarbonate is amorphous.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a photoreceptor for electrophotography, and more particularly to a laminated type photoreceptor for electrophotography in which a charge generation layer and a charge transport layer are provided on a conductive support. The present invention relates to a binder used in a charge transport layer.

Prior Art Conventionally, a so-called charge generation layer, which can generate charge carriers by light absorption, is placed on a conductive support, and furthermore, the generated charge carriers can be moved by the force of an electric field. Many laminated type electrophotographic photoreceptors provided with a so-called charge transport layer have been proposed.

In these laminated electrophotographic photoreceptors, the charge generation layer is generally formed by the method described in F.

1) Selenium (So), selenium alloy, amorphous sulfur (a-
A charge generating substance such as 8il pigment is formed by vacuum deposition, glow discharge, etc. (For example, JP-A-48-47838
No. 49-4833 April).

2) Prepare a dispersion of charge-generating substances such as 3e, 3e alloy, zinc oxide (ZnO), titanium dioxide (Code 102), cadmium sulfide (CdS), and organic pigments by adding a binder if necessary. Continue to apply. (For example, JP-A-47
No. 18543, No. 55-79449) 3) A solution of a charge generating substance, which is an organic pigment, dissolved in an organic amine is applied. (For example, JP-A-52-5!i (No. 343)) A charge transport layer is generally provided by dissolving a charge transport substance together with a binder in a solvent and applying it using an appropriate coating method. It goes without saying that the binder in this charge transport layer must provide good electrophotographic properties (charging properties, sensitivity, low residual charge, etc.), as well as the ability to withstand the electricity received during use. There is little deterioration due to physical, mechanical, thermal, and optical hazards, and there are no changes in characteristics due to the atmosphere.
This is due to the minimal change in characteristics during storage.

Conventionally, various polymeric materials have been proposed as the binder for forming this charge transport layer. For example,
polystyrene, styrene-acrylonitrile copolymer,
Styrene-butadiene copolymer, polyester, polyvinyl chloride, polyacrylate resin, styrene-maleic anhydride copolymer, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyvinylidene chloride, cellulose acetate,
Ethylcellulose, polyvinyl butyral, polyvinyl polymer, polyamide, poly-N-vinylcarbazole, polyvinyltoluene, acrylic resin, polycarbonate, silicone resin, poxy resin, melamine resin,
Thermoplastic 11 resins such as urethane resins, f-nor resins and alkyd resins, thermosetting resins, and natural products such as starch, glue, and zein are used singly or in combination.

Although some properties can be obtained by using these binders, they are not sufficient.

For example, when forming a photoreceptor for electrophotography, special +! 1, any of the following defects were observed.

1) Electrical properties 1j1 are excellent, but mechanical properties are poor.

2) Poor thermal stability.

3) The stability of the coating liquid dissolved in the solvent together with the charge transport substance is poor.

Therefore, conventional binders do not fully satisfy the required properties.
, :1 is not possible and IC0 objective.As a result of studying various materials as a binder for forming this electric dog transport layer, the present invention has developed a binder that does not have the above-mentioned drawbacks of conventional binders. The aim is to discover adhesives and provide photoreceptors using them.

Structure This invention provides a yt/C laminated type electrophotographic photoreceptor in which a charge generation layer and a charge transport layer are provided on a conductive support, in particular, the charge transport layer comprises a charge transport substance and a charge transport layer represented by the following structural formula. A polycarbonate resin (shown by the following structural formula (IF)) obtained from bisphenol Z and phosgene.

It is an electrophotographic photoreceptor containing.

The above-mentioned bisphenol/polycarbonate has good compatibility with various electrotransport materials, and when used, it is possible to obtain excellent Ic electrophotographic properties that are extremely stable electrically, mechanically, and thermally.

Furthermore, the primary coating solution forming the charge transport layer, consisting primarily of charge transport material, bisphenol-7 polycarbonate, and solvent, is very stable;
Since there is almost no change in characteristics over time, it can be used even if stored for a long period of time. Therefore, it is very advantageous in terms of productivity and cost.

Using this bisphenol 7 polycarbonate as a binder, C
Although the cause of this effect is not fully understood, polycarbonate 1-resin (generally obtained from bisphenol A) has superior mechanical and electrical properties compared to other polymer materials. In addition, the polycarbonate used in this invention is amorphous due to the presence of bulky groups such as cyclohexane in the molecule, making it difficult to change physical properties such as gelation and forming a thin layer. It is thought that this is because crystallization due to heat is less likely to occur in this case.

Below, each component of the photoreceptor of the present invention will be explained. First, as a conductive support, aluminum, nickel, chromium, soot oxide, indium oxide, etc. are deposited on a plastic film such as a polyester film, a polypropylene film, or a cellulose acetate film. Use a metal plate or tube made of aluminum, nickel, iron, etc. that has been treated to make it conductive.

The charge generation layer provided on this support is formed by depositing an inorganic semiconductor such as a 501Se alloy or a-3i, and a photoconductive organic pigment such as a phthalocyanine pigment, perylene pigment, or indigo pigment.
Provided by sputtering, glow discharge, etc.

Examples of the photoconductive organic pigments include CI Pigment Blue 25 [Color Index (CI > 211)].
80], CI Pigment Red 41 (CI 2
1200), Sea Eyed Red 52 (CI 4
5100), CI Basic Red 3 (CI
45210>, a nonozo pigment with a carbazole bone core (described in JP-A-53-95033), an azo pigment with a styrylstilbene bone core (described in JP-A-53-13)
3229), an azo pigment having a triphenylamine bone core (described in JP-A-53-132547), and an azo pigment having a dibenzothiamine bone core 1 (described in JP-A-54-21723). (described in Japanese Patent Application Laid-open No. 12742-1989), an azo pigment with an ox()-diazole bone core
(described in the publication), an azo pigment with a norolenone skeleton (
JP-A-54-22834), azo pigments having a bisstilbene skeleton (described in JP-A-54-17733), azo pigments having a distyryloki-4-nodiazole skeleton (described in JP-A-54-2129) , an azo pigment having a distyrylcarbazole skeleton (JP-A-54-17)
734), trisno7zo pigment having a carbazole skeleton (described in JP-A-57-19'5767 and JP-A-57-195768), and CI Pigment Blue 16 (C[74100]). ) and other phthalocyanine pigments, Sea Eye Butt Brown 5
(CI 73410), Thailand to Sea Ibara 1 (CI
73030), perylene pigments such as Argo Scarlet 1 to B (manufactured by Bayer AG), and perylene pigments such as Indanthrene Scarlet 1 to R (manufactured by Bayer AG), if necessary. For example, the binder and the like can be dispersed in a solvent and provided by coating or the like.

Binders used for this include polyvinyl butyral resin, polyvinyl formal resin, polyester resin, polycarbonate resin, polystyrene, polyvinyl acetate,
Polyvinyl chloride, polyamide, polyurethane, various celluloses, etc. can be used.

In addition, solvents such as benzene, 1-lune, xylene,
methylene chloride, dichloroethane, monochlorobenzene,
Dichlorobenzene, ethyl acetate, butyl acetate, methyl"
:Dilketone, dioxane, tetrahydrofuran, dimethylbormamide, cyclohexanone, methylcellosolve, -[tilcellosolve, etc.] and mixtures thereof.

The thickness of the charge generation layer formed by these methods is 0.05
A suitable r is about 20μ, preferably about 0.1 to 2μ.

The charge transporting substance provided on the surface of the charge generating layer (as a component of the charge transporting layer) and used together with the Nord Z polycarbonate-1 resin may be those used in conventional laminated electrophotographic photoreceptors. For example, poly-N-vinylcarbazole and its derivatives, poly-γ-carbazolylethylglutamate and its derivatives, pyrene-formaldehyde composite and its derivatives, polyvinylpyrene, polyvinicif-1-puntorene, Aki→nozole derivatives, oxadiazole derivatives. , imidazole derivative, 9
-(p-diedylinonominostyryl)anthracene, 1
．． Electron-donating substances such as 1-bis(4-dibenzylaminophenyl)propane, styrylanthracene, styrylpyrazoline, phenylhydrazones, α-stilbene derivatives, or fluorenone derivatives, dibenzothiophene derivatives, indenothiophene derivatives, phenanth Examples include electron-accepting substances such as lenquinone derivatives, indenopyridine derivatives, thioxanthone derivatives, benzo[C]cinnoline derivatives, phenazine oxide derivatives, tetracyanoethylene, tetracyanoquinodimethane, promanil, chloranil, and benzoquinone. For example, a known plasticizer and leveling agent are added, dissolved in a solvent such as tetrahydrofuran, dioxane, toluene, monochlorobenzene, dichloroethane, methylene chloride, etc., and coated on the direction generation layer. The appropriate thickness of the charge transport layer is about 5 to 100 microns.

The coating solution for forming a charge transport layer containing bisphenol 2 polycarbonate of the present invention is very stable and is particularly advantageous when forming a charge transport layer using a method that requires a large amount of coating solution, such as a dip coating method. becomes.

In the present invention, in order to improve interlayer adhesion and charging characteristics of the photoreceptor, a contact layer of polyamide, polyvinyl acetate, polyurethane, etc. is applied to the conductive support before forming the charge generation layer. (intermediate layer) or a thin layer such as aluminum oxide is coated or deposited using a conventional method such as J, S, 0.
．． It is possible to provide a thickness of about 0.01 to 2.0 μm.

Hereinafter, the present invention will be specifically explained with reference to Examples.

Example 1 A disazo pigment having the following structural formula (2) was used as a photoconductive organic pigment to prepare a coating solution for forming a charge generation layer having the following composition.

■ The coating solution was a disazo pigment with the structural formula (I [ After dispersing these components in a ball mill for 48 hours, 22.3 gr of tetrahydrofuran and 37.2 gr of ethyl cellosolve were further added and dispersed for 1 hour.

After dispersion, the millbase was taken out into a container and diluted and stirred so that the weight ratio of tetrahydrofuran and ethyl cellosolve was 4:6 and the solid content was 1 wt % to prepare a dispersion for coating.

Aluminum plate with a thickness of 0.51al11 (J I S
1070), the above coating dispersion was applied by a dip coating method and dried to form a charge generation layer having a thickness of about 0.5 μII (7).

Next, for the charge transport layer, prepare a coating solution with the following composition, apply it by dip coating method, and obtain a film thickness of 2011 m after drying.
A laminated electrophotographic photoreceptor was prepared using the following charge transport layer.

The coating liquid for the upper power distribution layer 1+111 uses a hydrazone compound of the following structural formula IV, and its composition is: Lahydrofuran 160g IC0 Comparative Example 1 Polyacrylate-1-resin (LJ
-100: manufactured by Unijika) was used, but the lamination 41' was carried out under exactly the same conditions as in Example 1! Created a photoreceptor for electrophotography.

Example 2 The following composition: Polyamide resin (copolymerized nylon CM-8000, Toshi) 10 gr
Coating solution of 19 hours of ethyl alcohol was applied to an aluminum plate with a thickness of 0.51 (JIS
1070) by a dip coating method and dried to form an intermediate layer with a film thickness of 0.5 μm.

Next, a coating solution for forming a charge generation layer having the following composition was prepared using the following trisazo pigment (represented by structural formula V) as a photoconductive pigment.

Trisazo pigment of structural formula V 3 gr Cyclohexylinone 51 g After dispersing the above raw materials in a ball mill for 48 hours, 90 qr of cyclohexanone was added and the mixture was further dispersed for 1 hour. After dispersion, the mill base was taken out into a container, tetrahydrofuran was added and -C1 solids 11 The mixture was diluted and stirred so that the concentration was 1 wt%, and a molecular II solution for coating was prepared.

Next, this dispersion was coated on the intermediate layer using a dip coating method, and a charge generation layer having a thickness of 0.5 μm after drying was provided.

Next, a coating liquid for forming a charge transport layer was prepared with the following composition,
It was coated on the surface of the charge generation layer by dip coating to form a charge transport layer having a thickness of 20 μm after drying. In this way, a laminated photoreceptor consisting of a conductive layer, an intermediate layer, a charge generation layer, and a charge transport layer was completed.

The coating solution for forming the charge transport layer was manufactured by the following formula #l and had a composition having the above structural formula % formula % tetrahydrofuran 160gr.

Comparative Example 2 As a coating liquid for forming a charge transport layer, bisphenol A polycarbonate, which is a component of the coating liquid for forming a charge transport layer in Example 2, was replaced with bisphenol A polycarbonate <K-1.
The materials and conditions were exactly the same as in Example 2, except that 300: Seiki Kasei) was used! I made a la layer type electrophotographic photoreceptor.

The coating liquid for forming a charge transport layer prepared in each of the above Examples and Comparative Examples was put into a container, sealed, and measured using a rotational viscometer (E-type viscometer, type EL, manufactured by Toki Sangyo) to determine the change in viscosity over time. was measured. The results are shown in Table 1.

In addition, the photoreceptor manufactured by the method of Example 1 and Comparative Example was tested using an electrostatic close-up machine test device [1 m Kawaguchi Electric Seisakusho 31]/1
28il! ] using the following article ('I”r test,
The electrophotographic properties were compared.

The test method was to perform a -6kV corona discharge for 20 seconds (
Charge it, measure the surface potential Vs (volts) at that time,
The surface potential Vo (
volts), and then irradiated with 20 lux white tungsten light to obtain an exposure rate of 1/10 (lux seconds), 1;
Then, the surface potential VO30 was measured 30 seconds after irradiation.

The binding is shown in Table 2 of 4ζ J0 As can be seen from these results, by using the bisphenol 7 polycarbonate of this invention, an extremely stable coating liquid can be obtained, and the electrophotographic properties are also better than those used conventionally. Even when compared with those using a binder that is similar to or better than that using a binder, similar or better results can be obtained.

Effects The electrophotographic photoreceptor of the present invention has superior properties as an electrophotographic photoreceptor compared to conventional photoreceptors, and is compatible with the coating liquid for forming a charge transport layer used to manufacture the photoreceptor. Since it is extremely stable, it is also advantageous in the production of photoreceptors.

Claims (1)

[Claims] In a laminated electrophotographic photoreceptor in which a charge generation layer and a charge transport layer are provided on a conductive support, the charge transport layer comprises a charge transport substance and a charge transport material represented by the following structural formula (I). A photoreceptor for electrophotography, characterized in that it contains a polycarbonate resin (represented by the following structural formula (I[)) (I[>) obtained from bisphenol and phosg]/.